A wireless communication system including a transmission device to transmit a wireless signal by using a beam forming technology and a reception device to receive the transmitted wireless signal is known (see, for example, Japanese Laid-open Patent Publication No. 10-023498, Japanese Laid-open Patent Publication No. 2002-152108, and Japanese Laid-open Patent Publication No. 2000-196328). The transmission device transmits a signal in which a radiation power level in each of directions selected from among different directions is larger than a radiation power level in each of the other directions.
Within directions, the above-mentioned wireless communication system searches for a direction nearest to a direction from the transmission device to the reception device. A process for searching, within directions, for a direction nearest to a direction from the transmission device to the reception device is expressed as a beam search process, for example.
In the beam search process, the transmission device transmits search signals in which respective selected directions thereof are different. Furthermore, the reception device receives the search signals. In addition, based on reception results of the respective search signals in the reception device, the above-mentioned wireless communication system selects a direction nearest to a direction from the transmission device to the reception device, from among the directions.